Usually, the most exciting thing in the Senkaku islands is the fate of the grey-brown mole, an endangered species. Then, every so often, politics intrudes. Anti-Japanese protests are growing in China over the cluster of islands in the South China Sea, whose ownership is disputed between the two countries. There has been little economic impact from the protests so far. But there are a lot of economic interests at stake for both sides if the dispute gets much worse.

China depends a lot on Japan’s technology and capital. Japan is its biggest foreign direct investor this year after Hong Kong. Nissanhas more than a quarter of its 190,000 global workforce there. Beijing will surely not want to put that dependency at risk. Nor will Tokyo: Japanese companies need China as a manufacturing hub – average manufacturing wages there are less than a tenth of those in Japan. One fifth of Japanese exports go to China.

Cynics could point out that Japan’s carmakers, for example, have been losing share in China over the past decade because of political tensions (protests over Japanese history textbooks in 2005, and more disputes over the Senkaku islands in 2010). Sales of Japanese cars in China have grown at an annual rate of 15 per cent over the past five years, compared with 25 per cent for total car sales. The market share of Toyotaand other Japanese peers in China now is just under a quarter – 7 percentage points down from 2008, according to LMC Automotive.